A problem of the present invention is to provide a skin collagen production-promoting agent without safety problems. Another problem of the present invention is to provide a skin collagen production-promoting food or drink product and a skin collagen production-promoting cosmetic product containing such a substance. TGF-β and/or a TGF-β degradation product, which is acquired by degrading TGF-β with a protease such as pepsin, pancreatin, etc., are used as a skin collagen production-promoting agent or the active ingredient of a skin collagen production-promoting food or drink product and a skin collagen production-promoting cosmetic product. The aforementioned TGF-β and/or TGF-β degradation product have an effect of increasing the collagen content of the skin.